Process of making phosphorus trioxid.



UNITED str TEsra'rENT OFFICE.

SAMUEL PEACOCK, or cHIc'AGo. ILLINOIS, Assmucn T0 'rnssoorns m ELECTRO- CHEMICAL coMPAuY, or New YORK, N. Y., A CORPORATION or NEW JERSEY.

success "or MAKING rnosrnonus mom.

No Drawing. '1

To all whom it may concern:

' elticient.

sr a or raters at n Patented Jan. 23, 1912. Application filed Jul 12, 1910. Serial 'No. 571,613. i

' The magnesia, the iron oxids, as

Be it known that I, Sumac Ifescocn, well as the alumina present are finally sep: a citizen of the United States, residing at Chicago, in the county of Cook and State 3 of Illinois, have invented certain new and a impure if the cheapmineral phosphates useful. lnun'ove'ments' in Processes of Making Phosphorus Trioxid; and I do hereby.

decl'a re the. fol lowin exact description v to be a full, clear, and the invention, such as will enable others skilled in the art to which 3 it appertains to make and use the same. This invention relates to the production 1 of phosphorus 'oxids from crude materials such 'as phosphate rock,bone ash or other arated out its-phosphates and therefore cause a loss of phosphorus. In addition to' the above, the final product is invariably quit-e have been used'as a base. According to myinvention, ll0\lf\'1, l;ll use of sulfuric acid is dispensed with, as well as the lixiviation and concentration stages of the process which are necessary in the sulfuric acid cheap sources of phosphorus, and has for its object to provide a method of fmanufac ture whiclrwill be more eflicient'and less expensive than the methods-heretofore proposed.

It is well known that mineral phosphate occurs in large deposits and is inexpensive, i

but it is not-pure. Its composition may be fairly said to be about 70 to 75 per cent. tri-v calcium phosphate, and about 25 to 30pm cent. carbonate of.lime, alumina, silica, iron oxids, etc. It is further well known that the oxids' of. hosphorus' are manufactured i at present 0 iefly by treating phosphate:

rock, bone ash, etc, with a Sufiicient quantity of sulfuric acid to combine with all of the lime of the phosphate.

The reaction i may be stated to be substantially as follows: 1

'021 130,-{ 3H SO,#3CaSO, l-2H,PO,. The lower oxid of phosphorus is also generally made vby reducing the higher oxid, or

mentis very costly, and is also not wholly without by the partiah pxidationof the phosphorus. It is further' v'vell known that this process ofproducing phosphorus oxids is costly, for valuable sulfuric acid is used up in forming sulfate of lune which has practically no commercial value. .The phospheric acid, however, that is thus produced is recovered as such by a complex system of lixiviation and concentration. Furthermore, upon extracting the acidulated hosoxids are readily extracted, yet other soluble. sulfates such as magnesium, iron and aluminium sulfates as well as more or less sulfates of lime go finto solution. These sulfates aregenerally separated out as far as possible by concentration in lead lined vessels, butzit is recognized that such treattreatment.

Furthermore, in my. invention.

there is no danger of iron, alumina, or mag v statbtlfsubstantially as follows;

I have found that this reaction is so complete as to -.be practically quantitative. The oxid of phosphorus in its state of volatilizetion is readily collected by any suitable process or it may be converted into phosphoric acid in any suitable and well known manner. I have.furtherdiscovered that not only miiy mixtures of phosphids and phosphat'es be used'as above tofree the oxids of phosphorus from its compounds,but that also free oxids of phosphorus are produced to a greater or less degree in the manufacture of calcium phosphid, provided the carbon be not used in excess in the furnace. The conversion, however, of crude phos- 'phatfes into free phosphorus oxids is not nearly so complete by such treatment as could be desired. I therefore prefer to malre calcium phosph id in a separate operation its equivalent. of tri-calcium phosphate, phate with water, although the phosp XOLHS '3 light red temperature.

whereupon I heat the mixture to at least a as calcium carbid now manufactured.

It is evident that those skilled in the art will'be'enabled to vary the details of car-- rying out my process within wide limits departing from the spizit of my n f and mix some 0t thesame with three times l i i l l I F l l trioxid which consists in .mixing'a calcium phosphid with a phosphate; in heating-the mixture until the'trioxid of phosphorus is termed; and 'in finally'suitably recovering the oxid thus obtained, substantially as described.

' 3. The process of producing'phosphorus trioxid which consists in mixing calcium phosphicl with substantially three times its equivalent oftri-calcium phosphate; rais-- ing themixtnre to a red heat; and in recovering the oxid of phosphorus thus obtained,

substantially as described.

In testimony whereof, I afiix my signature, in presence of two witnesses.

SAMUEL PEACOCK. VVitnesses:-

R. J. BOYLAN, T. A. \V rHnnsrooN. 

